Surgical repair with hook-and-loop fastener

ABSTRACT

Surgical repairs of torn or ruptured tendons and ligaments are made by re-fastening the torn or ruptured tendon or ligament with a biocompatible or bioabsorbable hook-and-loop fastener.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to surgical procedures generally and, moreparticularly, to orthopedic surgery. Specifically, this inventionrelates to an apparatus and method for the repair of torn or rupturedtendons or ligaments. The invention is described with respect to rotatorcuff and knee ligament repairs as being examples of the application ofthe invention, but the invention is useful for the repair of any torn orruptured tendon or ligament.

2. Description of the Prior Art

Human bones join with each other in a variety of ways to serve thefunctional requirements of the musculoskeletal system. Foremost amongthese needs is that of purposeful motion. The activities of the humanbody depend on effective interaction between normal joints and theneuromuscular units that drive them. The same elements also interactreflexively to distribute mechanical stresses among the tissues of thejoint. Muscles, tendons, ligaments, cartilage, and bone all do theirshare to ensure smooth function. In this role, the supporting elementsboth unite the abutting bones and position the joints in the optimalrelationship for low-friction load-bearing. Two importantcharacteristics of normal joint function are stability and lubrication.This invention describes surgical techniques for aiding in the return offunctioning to the musculoskeletal system following injuries involvingfor example the separation of a tendon from a bone or the rupture of atendon or ligament due to accident or injury or overuse.

Rotator Cuff Example

The rotator cuff is composed of four muscles that blend together to helpstabilize and move the shoulder. Loss of the integrity of the rotatorcuff is a common cause of shoulder weakness. Persons with significantrotator cuff defects have difficulty raising the affected arm orrotating it out to the side. Strong rotator cuff tissue requires a majorforce to tear it. Weakened degenerative cuff tissue can be torn easily,even while carrying out activities of daily living.

The young healthy cuff is highly resistant to disruption ordegeneration. Because of the change in cuff strength with age, fullthickness cuff lesions are most unusual under the age of 40. When cufflesions occur in the younger age group, they may be only partialthickness or they may include the avulsion of bone from the tuberosity.Disuse and scarring of the partial thickness lesion may lead tostiffness, limiting the range of elevation, cross-body adduction, andinternal rotation.

With increasing age and disuse, less force is required to tear the cuff.Often, the acute symptoms from progression of the cuff defect aredismissed as "tendinitis" or "bursitis." Once these transient symptomsresolve, the shoulder becomes asymptomatic, except for a relativelyimperceptible increment in weakness. It is not uncommon to encounterpatients with large cuff defects and minimal symptoms. If theseshoulders remain stable with the humeral head centered in the glenoid,they can demonstrate an astounding degree of function. Bilateraldegenerative cuff defects are common. In one study it was found that 55percent of patients presenting with a symptomatic cuff tear on one sidealso had a tear on the opposite side.

When rotator cuff tears are relatively recent and when a significantforce was required to tear the tendon, the chances of regaining shoulderstrength by rotator cuff repair surgery are good. Conversely, when thedefect is long-standing and has occurred without a major injury, rotatorcuff repair surgery may be a less preferred option. Thus, withlong-standing shoulder weakness from rotator cuff defects, an attempt atstrengthening the remaining muscles may be worthwhile before consideringsurgical repair.

Cuff failure may progress as major episodes of tendon tearing or ascreeping tears involving relatively few fibers at a time with thinningof the cuff tendon. Degenerative lesions of the cuff typically start atthe deep surface of the anterior insertion of the supraspinatus near thelong head of the biceps brachii. Once these lesions begin, it isdifficult for them to heal, because of the hostile environment, thecompromised vascularity, the large loads, and the large deformationsthat the healing tissue must endure. Failure of one fiber or of groupsof fibers places greater loads on the adjacent fibers, favoring theirfailure (the "zipper" phenomenon). When a tendon fiber fails, the musclefiber to which it attaches produces retraction away from the site ofdisruption, increasing the gap needing to be closed. This retractionalso places tension on the local vasculature leading to limitation oftendon blood flow in the area where healing is needed. Rotator cufftendon defects are subject to the effects of synovial fluid on boththeir articular and bursal sides; the fluid and its enzymes may removethe fibrin clot necessary for healing of the cuff lesion. In the absenceof repair, the degenerative process tends to continue through thesubstance of the supraspinatus tendon to produce a full thickness defectin the anterior supraspinatus tendon. This full thickness defect tendsto concentrate loads at its margin, facilitating additional fiberfailure with smaller loads than those which produced the initial defect.

Once a supraspinatus defect is established, it typically propagatesposteriorly through the remainder of the supraspinatus, then into theinfraspinatus and teres minor. Further propagation of the cuff defectcrosses the bicipital groove to involve the subscapularis, starting atthe top of the lesser tuberosity and extending inferiorly. As the defectextends across the bicipital groove, it may be associated with ruptureof the transverse humeral ligament and destabilization of the long headtendon of the biceps.

The concavity compression mechanism is compromised by cuff disease.Beginning with the early stages of cuff fiber failure, the compressionof the humeral head becomes less effective in resisting the upward pullof the deltoid. Partial thickness cuff tears cause pain on musclecontraction similar to that seen with other partial tendon injuries(such as those of the Achilles tendon or extensor carpi radialisbrevis). This pain produces reflex inhibition of the muscle action. Inturn, this reflex inhibition along with the absolute loss of strengthfrom fiber detachment makes the muscle less effective in balance andstability. The weakened cuff function allows the humeral head to riseunder the pull of the deltoid, squeezing the cuff between the head andthe coracoacromial arch. Under these circumstances, abrasion occurs withhumeroscapular motion, further contributing to cuff degeneration.Degenerative traction spurs develop in the coracoacromial ligament whichis loaded by pressure from the humeral head (analogous to the calcanealtraction spur that occurs with chronic strains of the plantar fascia).Upward displacement of the head also wears on the upper glenoid lip andlabrum, reducing their contributions to the effective depth of the upperglenoid and to glenohumeral stability from concavity compression.Further deterioration of the cuff allows the tendons to slide down belowthe center of the humeral head, producing a "boutonniere" deformity. Thecuff tendons become head elevators rather than head depressors. Once thefull thickness of the cuff has failed, abrasion of the humeral articularcartilage against the coracoacromial arch may lead to a secondarydegenerative joint disease known as cuff tear arthropathy.

The progression from partial thickness tear toward cuff tear can takeplace as a subtle and even subclinical degenerative process, with a fewfibers giving way at a time. It can also progress as a series ofepisodes interpreted as "tendinitis," "bursitis," or "impingementsyndrome." A more significant injury can produce an acute extension ofthe defect. It is important to note that cuff defects arising withminimal or no injury suggest that the cuff tissue is of poor quality andthus is more likely to fail again after surgical repair. By contrast,acute tears resulting from major injuries are more likely to involverobust tissue that is more amenable to a durable repair.

The disuse of torn tendon leads to scarring and atrophy of tendon andmuscle. Loss of cuff material from the degenerative process limits whatis available for repair. Local injections of steroids may furthercompromise the healing potential of failed cuff fibers. Once the humeralhead has started to subluxate superiorly, increased stretching loads areplaced on the residual tendons, tending to exacerbate the cuff defect.Long-standing superior subluxation leads to erosion of the upper glenoidlip, favoring continued superior subluxation even after cuff repair.Once the process of superior subluxation is established, stabilizationof the humeral head in its normal position is difficult even if a cuffrepair is achieved. In summary, rotator cuff defects are common causesof shoulder weakness.

Usually, cuff tears are associated with degenerative changes, which makethe tissue susceptible to failure with low applied loads, especiallythose applied eccentrically. Alternatively, cuff tears can occur instronger cuff tissue, but these injuries require the application of muchgreater loads. Cuff defects produce weakness of elevation and externalrotation as well as a possible loss of stability of the humerus againstupward displacing loads from the deltoid. Shoulders may be comfortableand able to carry out certain functions in the presence of significantcuff defects. Rotator cuff surgery can restore the strength of theshoulder if the cuff tissue is of sufficient quantity and quality. Tominimize the risk of retear, a substantial period of minimal loadingneeds to follow cuff repair surgery. Returning to heavy work after acuff repair risks the integrity of the repair. Preservation of deltoidfunction is essential in rotator cuff surgery. If the function of boththe cuff and deltoid are lost, glenohumeral arthrodesis may representthe only surgical option for salvage.

Surgical exploration and attempted cuff repair is an option for thepatient who understands the limitations of this procedure. Promptsurgical exploration of the rotator cuff is considered forphysiologically young patients with acute tears. Repair should becarried out before tissue loss, retraction, and atrophy occur. For tearsolder than 12 months, a period of stretching and gentle strengtheningexercises can indicate the potential for nonoperative management.Exploration is considered for patients with functionally significantweakness from longer-standing tears refractory to nonoperativemanagement, provided that their expectations are realistic.

The goal of cuff repair surgery is to improve the strength and muscularbalance of the shoulder. This operative procedure is considered when theshoulder demonstrates weakness from a cuff defect and when there appearsto be a substantial chance of improvement from such surgery, for examplewhere a physiologically sound cuff has been torn acutely by asubstantial injury. In this situation, the quality and quantity oftendon for repair should be excellent. By contrast, with chronic massivedegenerative tears the quantity and quality of the cuff are less likelyto be optimal for surgical repair. In this situation, the surgeon andthe patient must understand preoperatively the potential limitationsimposed by the tissue in the shoulder.

It must be remembered that there are several ways in which surgery mayworsen the function of a cuff-deficient shoulder. These need to bereviewed before each cuff operation. The most serious is compromise ofthe deltoid muscle. The deltoid may be compromised by nerve injury. Thisinjury may involve the intramuscular motor branches to the anteriorthird of the muscle resulting from a too-distal split of the muscle inthe surgical approach. Deltoid denervation may also arise from axillarynerve injury when searching for cuff tendons laterally and posteriorlyaround the quadrangular space. Normally the deltoid has a strong tendonof origin between its anterior and middle thirds. This tendon attachesto the anterior lateral corner of the acromion. Postoperative functionof the deltoid may be compromised by failure to achieve a strongreattachment of this tendon and the anterior muscle fibers afteracromioplasty. This is particularly a problem when a large anterioracromial resection is performed requiring stretch of the deltoid forreattachment. Failure of the anterior deltoid origin devastates the mostimportant motor for shoulder elevation.

The cuff is generally approached though an acromioplasty incision in theskin lines perpendicular to the deltoid fibers. This incision offers anexcellent exposure and the opportunity for a cosmetic closure,particularly in comparison with the skin incisions parallel to thedeltoid fibers. Great care is taken to preserve the tendon fibers of thedeltoid. The deltoid has an important tendon of origin between itsanterior and middle thirds. Arising from the anterior lateral corner ofthe acromion, this tendon is not only the guide to exposure of the cuff,but is also the key to reattachment of the deltoid origin at theconclusion of the surgery. This tendon is generally split longitudinallyfor 2 cm distal to the acromion in line with its fibers, taking care toleave some of the tendon on each side of the split. The split iscontinued up over the acromion and into the trapezius insertion. For 1cm on either side of this split the deltoid origin is sharply dissectedoff the acromion, so the strong bony attachment fibers remain with themuscle. These fibers provide a strong "handle" on the muscle, so a solidrepair can be achieved. Splitting the parietal layer of the bursa on thedeep aspect of the deltoid provides a view of the rotator cuff. Before a"reflex" acromioplasty is performed, the quality and quantity of thecuff tissue are observed to determine the likelihood of cuffreparability. Hypertrophic bursa and scar tissue are resected to allow agood view of the cuff tissue.

Cuff tears have been characterized based on the number of tendons torn.The quality of the cuff tissue may be characterized in terms of itsability to hold a strong pull applied to a suture passed through itsedge. Finally, it is critical to note the amount of tissue that has beenlost. The extent of tissue loss and the ability of the remaining tissueto hold suture are the major determinants of cuff reparability. Cufftears are also characterized by the size of the tear. A small tear isless than one centimeter, a moderate tear is between one and threecentimeters, a large tear is between three and five centimeters, and amassive tear is greater than five centimeters.

When a massive cuff defect coexists with a detached, denervated, ordysfunctional deltoid, a glenohumeral arthrodesis provides a salvageoption. By securing the humeral head to the scapula, the scapular motorscan be used to power the humerus through a very limited range ofhumerothoracic motion. A fusion technique may preserve all remainingdeltoid function.

If inspection of the cuff at surgery reveals good quality tissue insufficient quantity for a robust repair, primary glenohumeral stabilityfrom concavity compression can usually be restored. Thus, a standardanteroinferior acromioplasty is performed to improve exposure and toprotect the repair from abrasion. A flexible osteotome is directed sothat the anterior undersurface of the acromion is resected in the sameplane as the posterior acromion. Rough spots are smoothed with amotorized bur.

The goal of repair is a strong fixation of the tendon to the humerusunder normal tension with the arm at the side. The desired attachmentsite is at the sulcus near the base of the tuberosity. This goal isfacilitated by using three stages of sequential release. These releasesare required because the cuff is usually retracted and because tissue islost in chronic cuff disease. Unless these releases are carried out,increased tension in the repaired tendon will predispose to tightness ofthe glenohumeral joint and will additionally challenge the repair site.The humeral head is rotated to present the different margins of the cuffdefect through the incision, rather than enlarging the exposure to showthe entire lesion. The deep surface of the cuff is searched forretracted laminations. In prior art techniques, all layers of the cuffare assembled and tagged with sutures. By applying traction to thesesutures, the cuff is mobilized sequentially as necessary to allow thetorn tendon edge to reach the desired insertion at the base of thetuberosity. First, the humeroscapular motion interface is freed betweenthe cuff and the deltoid, acromion, coracoacromial ligaments, coracoid,and coracoid muscles. Next, the coracohumeral ligament/rotator intervalcapsule is sectioned around the coracoid process to eliminate anyrestriction to the excursion of the cuff tendons and to minimize tensionon the repair during passive movement. This release of the coracohumeralligament and rotator interval capsule also contributes to better thesurgical repair by mininizing the capsular tightening effect of cuffrepair. At this point the ease with which the cuff margins can beapproximated to their anatomic insertion at the base of the tuberosityis evaluated. If good tissue cannot reach the sulcus, the third releaseis carried out. This release divides the capsule from the glenoid justoutside the glenoid labrum, allowing the capsule and tendon of the cuffto be drawn further laterally toward the desired tuberosity insertionwithout restricting range of motion.

The surgeon first makes a judgment concerning the site at which the cuffcan be implanted into the bone without undue tension while the arm is atthe side. Ideally, the site of implantation will be in the sulcus at thebase of the tuberosity. In large cuff defects, a somewhat more medialinsertion site may be necessary. Often, when a medial insertion site isrequired for a large cuff defect, the new insertion lies in an areawhere the articular cartilage has been damaged by abrasion against theundersurface of the acromion.

Traditionally, the repair is accomplished as a tongue in groove, withthe cuff tendon drawn into a trough near the tuberosity, providing asmooth upper surface to glide beneath the acromion. This groove providesthe additional advantage that if some slippage occurs in the suturefixation of the cuff to bone, contact between the tendon and bone is notlost. Nonabsorbable sutures passed through the tendon margin are thenpassed through drill holes in the distal tuberosity so that the knotswill not catch beneath the acromion. The knots are tied over thetuberosities so that they will lie out of the subacromial space. Ifthere is a longitudinal component to the tear, it is repairedside-to-side with the knots buried out of the humeroscapular motioninterface. The repair is checked throughout a range of motion to 140degrees of elevation and 40 degrees of external rotation to assure thatit is strong, it is not under excessive tension, omial motion. Ifadditional resection of the undersurface of the acromion is required toallow smooth passage of the repaired tendon, it is performed at thistime.

Knee Tendon Repair Example

Knees are remarkable mechanisms, able to absorb three times the body'sweight with every step taken. But the rigor of sports added to everydaywalking can make the knees extra vulnerable to damage. Anyone can haveknee problems. Women are especially susceptible because their widerpelvis tends to make them knock-kneed.

The bones of the knee, the femur and the tibia, meet to form a hingejoint. The joint is protected in front by the patella (kneecap). Thejoint is cushioned by articular cartilage that covers the ends of thetibia and femur, as well as the underside of the patella. The lateralmeniscus and medial meniscus are pads of cartilage that further cushionthe joint, acting as shock absorbers between the bones.

Ligaments help to stabilize the knee. The collateral ligaments run alongthe sides of the knee and limit sideways motion. The anterior cruciateligament, or ACL, connects the tibia to the femur at the center of theknee. Its function is to limit rotation and forward motion of the tibia.A damaged ACL is replaced in a procedure known as an ACL Reconstruction.The posterior cruciate ligament, or PCL (located just behind the ACL)limits backward motion of the tibia. These components of the knee, alongwith the muscles of the leg, work together to manage the stress the kneereceives as one walks, runs and jumps.

The cartilage covering our joint surfaces is called articular cartilage.Normally, it is a smooth, well-lubricated surface that offers lessfrictional resistance than that of an ice skate gliding on ice. Normalcartilage is very durable and somewhat elastic providing a shockabsorber for our joints. Articular cartilage does not have a bloodsupply, rather it gets it oxygen and nutrients from the surroundingjoint fluid. When a joint is loaded, the pressure squeezes fluid,including waste products out of the cartilage and when the pressure isrelieved, the fluid seeps back in together with oxygen and nutrients.Thus, cartilage has a limited ability to repair itself.

Rupture of the quadriceps tendons is one of the more serious injuries tothe knee and is most common in senior citizens. It is probablyassociated with decreased vasculature. This type of injury is morecommon following cortisone injections or associated with diabetes orchronic renal failure, hyperthyroidism, and gout.

The tear may involve either portion of trilaminar tendon or its entiretyand usually the tear is initiated centrally and progresses peripherally.The tendon usually ruptures transversely at the osteotendinous junctionand the rupture often extends through the vastus intermedius tendon,proximal to the rupture of the rectus femoris tendon.

The level of the rupture usually corresponds to amount of flexion attime of injury. Superficial and deep tears rarely involve the trilaminarstructure at the same level. Unlike the Achilles tendon rupture, thequadriceps disruption is associated with intense pain.

The consequences of a tendon rupture in the knee may include largehemarthromis, a freely mobile patella and an impressive loss of extensorfunction. The patient is often unable to walk, may be unable to extendthe knee and may demonstrate a palpable defect.

The quadriceps tendon usually ruptures transversely just proximal topatella. With partial tears an extensor lag usually is present.

Surgery to repair a tendon rupture is performed within 48 hours ifpossible. Early intervention allows end-to-end repair of the tendon.Traditionally, fibers of the rectus femoris tendon are sutured tosuperior pole of patella through drill holes. Because rupture nearlyalways takes place early through an area of degeneration reinforcementmay be necessary.

One technique, known as the Scuderi method, involves making anteriorlongitudinal incision in midline of extremity to expose the rupture. Thetendon ends are apposed by extending knee and pulling the proximal partof tendon ddon are sutured together. A triangular flap is fashioned fromthe anterior surface of proximal part of tendon about 2-3 mm thick, 7.5cm long on each side, and 5 cm wide, leaving the base attached at apoint about 5 cm proximal to the rupture. The triangular flap is turneddown distally and it is sutured in place across rupture.

The prior art surgical procedures and materials rely upon sutures,staples, and/or anchors for attaching tissue to tissue and tissue tobone. Sutures are often very difficult to apply and sometimes surgerybeyond making the repair per se is necessary to enable the surgeon tofix and tie the sutures. The result is increased trauma for the patientand due to the additional surgery and the time required to perform theoperation. Suture placement is a demanding and exhausting effort for thesurgeon.

Staples offer some simplification for certain fastening operations;however, stapled attachments may lack sufficient strength for manyprocedures and may increase the trauma of the surgery where staples areplaced in bony structures.

SUMMARY OF THE INVENTION

It is an object of this invention to provide an improved surgical methodfor repairing a torn or ruptured tendon or ligament by attaching thetendon or ligament to a boney structure or to another tendon or ligamentportion.

It is another object of this invention to provide a velcro-type fastenerfor use in surgical repair of a torn or ruptured tendon or ligament.

BRIEF DESCRIPTION OF THE PREFERRED EMBODIMENTS

In accordance with one embodiment of the present invention, a method forre-attaching at least one of a tendon and ligament to bone is disclosed.The method comprises the steps of: exposing an unattached portion of atleast one of a tendon and ligament requiring attachment; exposing anattachment site on a bone for the unattached portion of the at least oneof a tendon and ligament requiring attachment; affixing at least one ofa hook component and loop component of a hook and loop fastener to theunattached portion of at least one of a tendon and ligament requiringattachment; affixing a complementary component of the hook and loopfastener to the attachment site for the unattached portion of the atleast one of a tendon and ligament requiring attachment; and fasteningthe components of the hook and loop fastener.

In accordance with another embodiment of the present invention, a methodfor repairing a mid-substance tear is disclosed. The method comprisesthe steps of exposing a first unattached portion of at least one of atorn tendon and ligament; exposing a second unattached portion of the atleast one of a torn tendon and ligament; affixing at least one of a hookcomponent and loop component of a hook and loop fastener to the firstunattached portion of the at least one of a torn tendon and ligament;affixing a complementary component of the hook and loop fastener to thesecond unattached portion of the at least one of a torn tendon andligament; and fastening the components of the hook and loop fastener.

In accordance with a further embodiment of the present invention, abioabsorbable hook-and-loop fastener is disclosed. The fastenercomprises, in combination: a first component comprising hooks located ona sheet material; a second component comprising loops on a sheetmaterial; and each of the sheet material, hooks and loops consistingessentially of a material suitable for use in tissue repair.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a posterior view of the skeletal bones of the human shoulder.

FIG. 2 is an anterior view of a portion of the musculoskeletal structureof the human shoulder showing an example of a torn rotator cuff.

FIG. 3 is another anterior view of a lesser portion of themusculoskeletal structure of the human shoulder showing the attachmentof hook-and-loop fasteners for attaching one of the muscles of therotator cuff to the greater tubercle of the humerus.

FIG. 4 is a posterior view of a portion of the musculoskeletal structureof the human shoulder showing the attachment of three of the muscles ofthe rotator cuff to the greater tubercle of the humerus.

FIG. 5 is a posterior view of a portion of the musculoskeletal structureof the human shoulder showing the attachment of one of the muscles ofthe rotator cuff to the greater tubercle of the humerus using ahook-and-loop fastener.

FIG. 6 is a posterior view of a knee showing a portion of themusculoskeletal structure thereof.

FIG. 7 is an side, cross-sectional view of a knee showing a portion ofthe musculoskeletal structure thereof.

FIG. 8 is an anterior view of a knee showing a portion of themusculoskeletal structure thereof, depicting a torn quadriceps tendonand the securement of hook-and-loop fastener components to the tendon orligament and to the femur, respectively, for fastening the tendon orligament to the femur.

FIG. 9 depicts the quadriceps tendon and the femur with a hook-and-loopfastener attached thereto for attaching the tendon to the femur.

FIG. 10 depicts the attachment of the ends of a ruptured achilles tendonusing a hook-and-loop fastener.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

This invention is described by way of examples, i.e., the attachment ofrotator cuff muscles, quadriceps tendon and the joining of the ends of aruptured tendon. It is to be understood, however, that the invention isnot limited to these procedures or structures but, rather, is of generalapplication in the attachment of tissue to bone or tissue to tissue.Moreover, while the examples given herein relate to the human anatomy,the invention disclosed and claimed herein may be used for tendon andligament repair with other mammals as well.

The first example of the use of this invention is the attachment ofrotator cuff muscles and in the case of a torn rotator cuff. Thisexample is described by reference to FIGS. 1-5, inclusive. Thephysiological structures of interest here are shown in the figures. Thehumerus 2 and the scapula 4 form a universal pivot joint between thehead of the humerus 2 and the glenoid cavity 6 of the scapula 4.Referring specifically to FIG. 1, three of the muscles of the rotatorcuff have posterior origins indicated generally at 8 on the greatertubercle 10 and on the scapula 4.

Referring to FIG. 2, the subscapularis muscle 12 extends anteriorlybetween the scapula 4 and the greater tubercle 10. FIG. 2 depicts a tornsubscapularis tendon 20 separated from the greater tubercle 10. FIG. 3depicts, in enlarged view, the fixation of a hook-and-loop fastener 21for reattaching the subscapularis tendon 20 to the greater tubercle 10,one portion of the fastener 21 being attached to each of suchstructures. For example, the hook portion 22 of the fastener 21 is shownfixed to the greater tubercle 10 and the loop portion 24 is shown fixedto the tendon 20.

Referring to FIG. 4, the attachment of two of the rotator cuff muscles,the infraspinatus muscle 14 and the teres minor muscle 16, are shownattached to the humerus 2 by a hook and loop fastener 26, the mode ofattachment being depicted in more detail in FIG. 5 wherein the twocomponents 28 and 30 of the fastener 26 are shown fixed to the teresminor muscle 16 and the humerus bone 2, respectively. Attachment may bemade by means of hook-and-loop fastener 26 alone, as shown in FIG. 4, orin combination with existing suturing or anchoring techniques.

FIGS. 6 through 9 depict another exemplary application of the inventionfor reattaching the quadriceps tendon 110 to the femur 102. The kneejoint 100, as depicted in FIGS. 6, 7 and 8, includes the ends of thefemur 102 and the ends of the tibia 104 and the fibula 106. The kneejoint 100 permits bending essentially in one plane. Extension of theknee results in substantial part from the contraction of musclesapplying a shortening force over the anterior portion of the knee bymeans of the quadriceps tendon 110 and the patellar ligament 112, whichattach to the kneecap or patella 114. When the quadriceps tendon 110becomes detached from the femur 102, as shown in FIG. 8, repair requiresreattachment of the quadriceps tendon 110 to the femur 102.Traditionally, as discussed above, the attachment is made with suturesand/or staples. According to this invention, the attachment is made bymeans of a hook-and-loop fastener 126, the two components thereof beingshown at 120 and 122 in FIGS. 8 and 9. Attachment may be made by meansof hook-and-loop fastener 126 alone, as shown in FIGS. 8 and 9, or incombination with existing suturing or anchoring techniques.

As discussed above, it is not uncommon for the quadriceps tendon 110 torupture adjacent the patella 114. Referring now to FIG. 10, it is alsonot uncommon for other tendons or ligaments, and in particular anachilles tendon 130, to rupture--a so-called "mid-substance tear." Insuch cases, it is necessary to effect a satisfactory repair to join theends of the achilles tendon 130 together. This is usually accomplishedwith sutures with or without additional reinforcement. According to thisinvention, the two ends of the achilles tendon 130 are joined togetherby a hook-and-loop fastener 136, alone or in combination with sutures oranchors (not shown), the two interacting portions of which fastener 136are shown in FIG. 10 at 132 and 134.

It is emphasized that the technique of this invention may be used toattach any tendon, and some other tissues, to a bone or to anothertendon or ligament or tissue.

Hook-and-loop fasteners are well-known and have found many applicationsbut, to the knowledge of the inventor, have never been considered to beuseful in tissue to bone or tissue to tissue surgical attachments.Commercially available hook-and-loop fasteners, a popular brand of whichare VELCRO® fasteners, are not useful in the present invention; however,the same techniques used in manufacturing commercial hook-and-loopfasteners can be used to manufacture fasteners of this type of materialsthat are compatible with tissues, bones and fluids and can remain in thepatient indefinitely or which are bioabsorbable and are assimilated bythe body after the tissue regenerates. Further, these devices can beformed, in part, in situ, using fast drying adhesives such as fibringlue which attach the fastener to the bone or other tissue and alsoattach the hooks or loops to the bone or tissue.

Many polymers are known to be biocompatible. For example DACRON®polyester is widely used as suture material and in implantable surgicaldevices. Polycarbonates are also generally compatible with biologicaltissue, etc. These and other materials can be formed into hook-and-loopfastener components using standard manufacturing methods.

Non-toxic, non-immunogenic, and bioabsorbable materials can also bemanufactured or formed as hook-and-loop fasteners. Suitable materialsinclude polylactic acid; polycaprolactone; polyglycolic acid;polyanhydrides (e.g., polyterephthalic acid/sebaic acid anhydride,polydioxanone); polyamino acids (e.g., polyglycine, etc.); andcopolymers of lactic acid with comonomeric materials such as glycolicacid, hexamethyl sebacic acid, etc. These combine the best qualities ofnon-immunogenicity, non-toxicity and an acceptable rate of bioabsorptionvs. regeneration of tissue and are preferred to prepare the surgicalimplant fasteners of the invention. Collagen and other polymers ofbiological origin (alginates, starch, etc.) are also suitable but have apotential of being immunogenic. Modified natural polymers such asgelatin, oxidized cellulose, etc., may also be utilized. Hydroxyapatitecoral may also be used. Additives may be incorporated in the fastener,materials such as plasticizers, citrate esters, hexametholsebacate,antibiotics (e.g., tetracyclines, penicillins, mefronidazole,clindamycin, etc.), to prevent infection, etc., or to accomplish otherdesired conditions or results.

Other biocompatible and bioabsorbable materials are described, alongwith methods of manufacture and handling, in the following patents andpublications, the disclosures of which are incorporated herein.

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Chavpil M. et al, "Medical and Surgical Appliances of Collagen" fromInternational Review of Connective Tissue Research, vol. 6 1973 pp. 1-6,9-10, 29-30 and 53-54.

The hook-and-loop fasteners may be fixed to the bone or tendon orligament using fibrin glue alone or in association with sutures and/orstaples. Even in those instances where suturing or stapling is required,the use of this invention permits operative techniques that are lessintrusive and less traumatic. Sutures or staples may be used only fortemporarily securing the fastener components while the fibrin or otherbiocompatible adhesive sets. In such instances, less stapling and lesssuturing than would be required if the entire attachment was made ofsutures or staples, or a combination of the two.

Importantly, from the operative time and trauma points of view, it iseasier to attach the respective components of the hook-and-loopfasteners to, e.g., the bone or to the end of a torn tendon or ligamentthan it is to use staples or sutures to attach the ligament to the boneor the ends of a ruptured tendon or ligament to each other.

Another important feature of this invention is that sterilehook-and-loop material may be cut at the operating table into exactlythe size and shape needed to obtain the best attachment.

Additionally, sterile hook-and-loop material can be cut not only to formthe attachment per se but in lengths and/or widths to providereinforcement for weakened tissue or bone.

Still another advantage is attainable using this invention. If thetendon or ligament rupture or tear is such that the tendon or ligamentis shorter than is needed to form a satisfactory attachment, thehook-and-loop material may extend beyond the end of the ruptured tendonor ligament, thus making an attachment at the proper length.

In carrying out the method of this invention, traditional surgicaltechniques for the particular repair may be used and the surgicalprocedure is the same as in traditional surgery with the exception thatthe attaching step comprises fixing one component of a hook-and-loopfastener to the tendon or ligament to be fastened and the othercomponent of the hook-and-loop fastener to the bone or tendon orligament to which the tendon or ligament is to be fastened and thenattaching the two components of the hook-and-loop fastener together bypressing the hook face to the loop face of the respective components.

The invention is also embodied in a bioabsorbable hook-and-loop fastenercomprising a first component comprising hooks on a sheet material and asecond component comprising loops on sheet material, the sheet material,hooks and loops consisting of a material suitable for use in tissuerepair.

Again, the foregoing are exemplary and the invention may be carried outusing any of many materials to repair virtually any tendon or ligamenttear or rupture.

What is claimed is:
 1. A bioabsorbable hook-and-loop fastener comprising, in combination:a first sheet of material; a first component comprising hooks located on said first sheet of material; a second sheet of material to be integrally connected to said first sheet of material; a second component comprising loops on said second sheet of material; and each of said first sheet and said second sheet of material, said hooks and said loops consisting essentially of tissue repair material, said hooks and said loops located opposite each other to facilitate coupling of said hooks to said loops.
 2. The fastener of claim 1 wherein said tissue repair material comprises a collagen-based material.
 3. The fastener of claim 1 wherein said tissue repair material comprises hydroxyapetite coral.
 4. The fastener of claim 1 wherein said tissue repair material comprises a non-immunogenic bioabsorbable polymer.
 5. The fastener of claim 1 wherein said tissue repair material comprises a biocompatible polymer. 